A Study to Learn How Well Dupilumab Works in Adult and Adolescent Participants With Eosinophilic Gastritis With or Without Eosinophilic Duodenitis and the Side Effects it May Have

About

Brief Summary

This study is researching an experimental drug called dupilumab. The study is focused on participants with active eosinophilic gastritis (EoG) with or without eosinophilic duodenitis (EoD). Participants with EoD only are not eligible for enrollment. EoG and EoD are uncommon, persistent, allergic/immune diseases in which eosinophils (a type of white blood cell) gather in large numbers in the stomach and small intestine and cause inflammation and damage.

The aim of the study is to evaluate the effect of dupilumab on relieving EoG (with or without EoD) symptoms and reducing inflammation in the stomach and, if applicable, small intestine in adults and adolescents aged 12 years and older after at least 24 weeks (about 6 months) and up to 52 weeks (1 year) of treatment.

The study is looking at several other research questions, including:

What side effects may happen from taking the study drug
How much study drug is in the blood at different times
Whether the body makes antibodies against the study drug (which could make the drug less effective or could lead to side effects)

Primary Purpose

Treatment

Study Type

Interventional

Phase

Phase 2/Phase 3

Eligibility

Gender

All

Healthy Volunteers

No

Minimum Age

12 Years

Maximum Age

N/A

Key Inclusion Criteria:

Adolescent participants will only be enrolled at study sites in countries/regions as permitted by local regulatory authorities and ethic committees (ECs)
Documented endoscopic biopsy supporting a pathologic diagnosis of Eosinophilic gastritis (EoG) at least 3 months prior to screening
Screening endoscopic biopsies with a demonstration of eosinophilic infiltration for a diagnosis of EoG, as defined in the protocol
Completed at least 11 of 14 days of EoG/EoD-SQ eDiary data entry in the 2 weeks prior to the baseline visit
History (by participant report) of at least 2 episodes of EoG (with or without EoD) symptoms per week in 8 weeks before screening, as defined in the protocol
An average TSS of ≥ 20 calculated using data collected via the EoG/EoD-SQ eDiary per week for the 2 weeks prior to baseline. An average severity score of ≥4 (on a scale of 0-10) per week for the 2 weeks prior to baseline for at least 2 of the 6 symptoms, as defined in the protocol.

Key Exclusion Criteria:

Body weight less than 40 kg at screening
Prior participation in a dupilumab clinical trial, or past or current treatment with dupilumab
Helicobacter pylori infection
Any esophageal stricture unable to be passed with a standard, diagnostic, upper endoscope or any critical esophageal stricture that requires dilation at screening
History of achalasia, Crohn's disease, eosinophilic colitis, ulcerative colitis, celiac disease, and prior gastric or duodenal surgery, as defined in the protocol
Other causes of gastric and, if applicable, duodenal eosinophilia or the following conditions: eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) or hyper-eosinophilic syndrome
History of bleeding disorders, esophageal or gastric varices that, in the opinion of the investigator, would put the participant at undue risk for significant complications from an endoscopy procedure
Initiation or change of a food-elimination diet regimen or re-introduction of a previously eliminated food group in the 4 weeks prior to the screening visit. Participants on a food-elimination diet must remain on the same diet throughout the study
Planned or anticipated use of any prohibited medications and procedures during the study
Planned or anticipated major surgical procedure during the study
Receiving tube feeding or parenteral nutritional at screening